how to get all attributes in prestashop

I need to get all attributes that exists in my Prestahop store not
matter wich or what product is assigned I just want to generate a
array of those attributes and then use them in ProductController.php
class. I check the file classes/Product.php and a method called
getDefaultAttribute($id_product, $minimumQuantity = 0) is present but
I think this only works for attributes assigned to a specific product
and not return all as I need. Any help? I'm newbie with Prestashop and
need to learn a lot of things

I need to get all attributes that exists in my Prestahop store not
matter wich or what product is assigned I just want to generate a
array of those attributes and then use them in ProductController.php
class. I check the file classes/Product.php and a method called
getDefaultAttribute($id_product, $minimumQuantity = 0) is present but
I think this only works for attributes assigned to a specific product
and not return all as I need. Any help? I'm newbie with Prestashop and
need to learn a lot of things

i have prestashop 1.5 installed on server A, on server B there is
prestashop 1.4 installed with thousands of products and database size
is about 500mb. I want to import all those products, categories,
customers and their addresses from 1.4 installation to 1.5
installation. I have access to both servers. CSV export for products
is taking like forever what should i do to import this all to 1.5.

In the common situation where classes are embedded as attributes of
other classes, what is the best way to check for nulls?

To illustrate what I'm talking about, say I want to access
this.getObject1().getObject2().someMethod() where
getObject1() or getObject2() could return
null. Right now I am doing the following, and it's ugly,
and there has to be a better way: